Strontium and Barium in the Triassic Limestone of the Opole Silesia Deposits

Abstract

Abstract This article presents the results of studies of strontium and barium content in Triassic (Muschelkalk) carbonate rock samples taken from the area of the Polish part of the Germanic Basin (the area of Opole Silesia). Sr and Ba were determined in the rocks of all formations of the Lower Muschelkalk - Gogolin Beds, Górażdże Beds, Dziewkowice (Terebratula) Beds and Karchowice Beds. Strontium and barium are chemical elements characteristic for aragonite carbonate phase. Aragonite is unstable calcium carbonate phase which is transformed such as high-Mg calcite into low magnesium calcite during diagenesis. So as Sr and Ba indicate the presence of aragonite in the primary carbonate material. Now these elements concentrate in low-Mg calcite crystal structure. The Triassic rocks of Lower Muschelkalk which are mined in different quarries of the Opole Silesia area are mainly built of low-Mg calcite with lower amounts of high-Mg calcite, protodolomite, ordered dolomite and huntite. There are smaller addition of non-carbonate minerals - quartz, chalcedony, muscovite, feldspars and iron minerals. The presence of Sr and Ba now bound in a structure of low-Mg calcite will indicate the occurrence of aragonite in the primary carbonate material. The Triassic rocks from the area of Opole Silesia were studied to determine the rocks enriched in Sr and Ba. Selected rock samples were examined using ICP AES spectrometry, XRF analysis and microprobe measurements. The results of studies show that strontium and barium occur in rocks of all Lower Muschelkalk formations. The lowest contents of these elements were determined in rocks of Gogolin Beds, higher - in rocks of other formations. The results of studies show that Sr and Ba concentrate in low-Mg calcite which dominates in Lower Muschelkalk rocks. Limestone built mainly of low-Mg calcite or “pure” calcite without substitution of other elements, especially Mg, Fe, Si and Al could be applied in lime industry or in other branches of industry, where pure quality raw material, without substitutions is needed.